11.6      Metering of Power

Each substation at BWI Marshall and Martin State Airports shall be provided with secondary watt-hour demand meters. All watt-hour demand meters shall have digital readout and pulse output for future remote monitoring.

Watt-hour meters shall be provided by tenants drawing 150 kVa electrical load or more. These meters must be compatible with MDOT MAA Power Monitoring System (Square-D Power Logic System). A one (1) inch conduit with communication cable shall be installed from each meter to the nearest approved MDOT MAA power monitoring closet. All other tenants drawing less than 150 kVa electrical load shall provide a one (1) inch conduit from their electrical panel to the nearest approved MDOT MAA power monitoring closet.

Metering at substations shall be compatible with Square-D Power Logic System.

For double ended substations, a meter shall be provided on each side of the double ended switchgear. A meter shall be provided for each breaker in the substation. Meter shall measure all of the following: voltage; current; power; power factor; frequency; kilowatt-hours; and demand. Unit shall have the following additional features: four (4) optically isolated status inputs; two (2) optically isolated RS485 communications ports; and Modbus and DNP communications protocol. In addition, one meter in any group shall have an internal modem. An auxiliary contact on each main and tie circuit breaker shall be wired to the status inputs on one power meter. The transformer over-temperature alarm on each transformer shall be wired to a status input on the associated power meter. The RS485 ports on all meters shall be daisy-chained together. With prior coordination with MDOT MAA’s Office of Information Technology, a category six (6) communication cable with one spare cable shall be extended from the meter with the internal modem to the nearest MDOT MAA communication closet.